Automatic telephone system



Nov. 10, 1925.

R. G. RICHARDSON AUTOMATIC TELEPHONE SYSTEM Filed Nov. 23, 1920 4 Sheets-Sheet l Q R &

R. G. RICHARDSON AUTOMATIC TELEPHONE SYSTEM Filed Nov. 23, 1920 4 Sheets-Sheet 2 Inuen' In? Hucfnag Efimhardsun R. G. RICHARDSON AUTOMATIC TELEPHONE SYSTEM Nov. 10, 1925- Filed Nov. 25, 1920 4 Sheets-Sheet 5 R. G- RICHARDSON AUTOMATIC TELEPHONE SYSTEM 4 Sheets-Sheet 4 Filed Nov. 25, 1920 E I E :Zzi: E:

Inusn U1" Burfnag Efimhardsnn $4. 7% fir? Patented Nov. 10, 1925.

i r 1,560,858 I U I STATES PATENT OFFICE."

I RODNEY RICHARDSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO AUTOMATIC ELECTRIC COMPANY, 01 CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

AUTOMATIC TELEPHONE SYSTEM.

Application filed November 23, 1920. SerialNo. 426,011;

and State of Illinois, have invented certain new and useful Improvements in Automatic Telephone Systems, of which the following is a specification.

The present invention relates in general *to automatic telephone systems in which directively controlled automatic switches are employed to establish connections between calling and called subscribers lines; and the principal object is to provide a new and improved system of finder switches for extending calling lines into connection with trunk lines, the finder switches, used having both.

primary and secondary selecting movements. and being adapted to performboth movements simultaneousl A further object is to provide anew and improved first selector switch adapted for use in exchanges where the trunking capacit required exceeds 1,000 or 10,000-lines, but diies not exceed twice the figures named, the new switch being adapted to perform a group selecting operation controlled by relays in which either one of two groups of twenty-five trunk lines each may be selected,

and a trunk selecting operation in which the first idle trunk in the selected group is taken for use.

A third object is to provide a selector switch, which may be a first, second, or third selector, having improved circuit arrangements and characterized especially by a test circuit arrangement in which the idle condition of trunk lines is indicated by a battery potential, instead of a ground potential.

The improved selectors above referred to the accompanying drawings forming a part' thereof.

In the drawings, Figs. 1, 2, and 3 are circuit diagrams of the essential apparatus in a telephone system embodying the principles ot' the invention Fig. 4 is a conventional drawing showing certain mechanical details of the finder switch. Fig. '5 is a different view of certain parts shown in Fig. 4.

Referring first to Figs. 1,. 2, and 3, these circuit diagrams shOW a plurality of serially related automatic switches which may be used to establish a talking connection between the substation A, Fig. 1, and the substation A, Fig. 3. The series of switches comprises thefinder switch'F, Fig. 1, the first and second selectors D and E, Fig. 2, and the connector H, Fig. 3.

The automatic telephone substations A and A are of the usual type and have the usual talking instrumenta-lities and calling devices for controlling the central ofiice switches. At the exohange each line is provided with a combination line and out-ofl' relay. Inthe case of the line of'su'bstation A, this individual relay is indicated by the reference character 16. Thelines are divided into groups of 100 lines each in accordance with the capacity of the connector and finder switches, and in addition to the individual line relays there are 10 tens relays and 10 units relays for each group, each of the tens relays being common to all of the lines of the group which terminate in the bers. The tens and units relays associated with the line of substation A are indicated by thereference characters 17 and 18, respectively. It' may be stated that the func tron of the tens and units relays is to indicate by their joint action thecalling condition of any calling line in the banks of the finder switches.

' The finder switch F, the selector E, and.

the connector H areof the well known Strowger vertical and rotary type so far as their mechanical construction is concerned, and hence will not need to bedescribed in detail. The construction of the finder switch, however, has been clmuged somewhat in order to permit it to perform its vertical and rotary selecting o rations simultaneously, and these modi ications will be explained Shortly. switches named are shown complete in the drawings and will be fully described.

The first selector D is similar in construction to a well known type of rotary line The circuits of all the,

V 9 turns the shaft by means of a rod 307. This switch. It hastwo sets of and a double bankwith 25 contact sets associated with each set of wipers. The wipers normally rest on the contact sets last'used and move in -.a forward direction only. The primary or group selection performed by this first selector is controlled entirely by I means of relays, that is, there is no primary stepping movement, and the group selecting operation consists merely in selecting one or the other of the two sets of wipers. The circuits are shown in full, and will be described.

Referring now to Fig. 4,- the mechanical construction of the finder switches will be considered a little more in detail. In general these switches are similar to the well known Strowger vertical and switches, as stated, and have the usual switch frame, banks, and operating magnets. The essential differences, or modifications, have to do principally with the shaft and wipers, and are rendered necessary by the fact that the vertical and rotary selecting operations are to be performed simultaneously. The drawing, therefore, shows only the lower portion of the shaft of one of these finder switches, together with the wipers andassociated sets of bank contacts. The drawing is nota working drawing. It is more or less conventional,

I and is intended only to illustrate the theory of operation. To proceed, the shaft 300 corresponds in general to the usual switch shaft, in this type of switch, and has the usual vertical ratchet teeth indicated by the reference character 301. These ratchet teeth are cut in a cylindrical hub or sleeve which is a shaft is broken away just above the collar;

not fixed rigidly to the shaft, but on the contrary is rotatable thereon, being held in place so far as longitudinal movement on the shaft is concerned by a collar 320. The

by means of the rotary ratchet wheel 302. This rotary ratchet'wheel does not rise with .the shaft in its vertical movement as is the usual practice, but is loosely mounted 'on then, theshaft simply rises through the ratchet wheel 302 and the latter remains stationary. The rotary ratchet wheel 302 extends vertically between twohori- ,zontal members 305 and 306, which are securely clamped to the shaft 300 by means of set screws, and fits loosely in a holenear the enter circumference of the rotary ratchet rotary wheel 302. It will be seen now that since the vertical hub carrying the teeth 301 is rotatable uponthe shaft and since the shaft is movable longitudinally relative to the rotary ratchet wheel 302, the shaft can be raised vertically and rotated at the same time. i

In- View of the-above it will be evident that the ordinary wiper construction cannot be used, since if the wipers were permanently r A pin.313" passes through a hole in the main shaft just below the auxiliary shaft and pre-- vents the latter from slipping down. The horizontal member 310 is clamped to the auxiliary shaft near the top and is normally held against the downwardly projecting arm 309 by means ofa small clock spring which is enclosed within the circular cup spring casing 308. One end of the spring is attached to the casing and the other end is attached to the top of the auxiliary shaft,

while the casing itself is rigidly secured to the main shaft 300'. This arrangement, in cluding the-casing 308 and. the spring "en closed therein, is similar to the cup spring assembly generally used at the top of the shaft. {it the right the horizontal member 310 carries. a roller 321 which is normally locked behind the forward extending latch portion of armature 322. Fig. 5 shows how the roller 321 and armature 322 look when viewed from .the top, and with the 'aid of this view the construction will be readily understood. When the vertical and rotary magnets are operatedsimultaneously, the former raises thev shaft vertically by means of. the

vertical teeth 301, and the latter rotates the shaft by means of the rotary ratchet wheel 302. The main shaft 300 rotates Within the vertical hub carrying the teeth 301 and slides longitudinally through the rotary ratchet Wheel 302. The auxiliary shaft 312 rises vertically with the main shaft but does not rotate, being prevented from so doing by the engagement of the roller 321 with the latch portion 'of armature 322. While the vertical movement continues, then, the roller 321 will simply ride up on this latch and the rotation of the main shaft will have no eflfect other than to tension the cup-spring connecting the two shafts. At the end of the vertical movement, the magnet 52 associated with armature 322 is auto matically energized, and the roller 321 is re-v leased. As a result the auxiliary shaft is instantly rotated around on the main shaft until the member 310 strikes against the arm 309 when the two shafts will be in their normal relation to each other. If the rotary selecting movement has already stopped the switch wipers will now be in engagement with the proper set of contacts, but if the,

rotary selecting movement has not been completed it will continue as usual, and both main and auxiliary shafts will be rotated simultaneously and as a single unit; vIt should be mentioned that the member 306. carries a pair of contact springs54 and 55, which are normally closed. These springs separate as soon as the main shaft starts .to rotate and are closed. again when the auxiliary shat't resumes its normal position after being released by armature 322.

The test wipers are indicated by the referencecharacters 93 and 94, the former being the tens or vertical wiper, while the latter is the units or rotary test wiper. The rotary test bank consists of eleven test contacts, ten of which correspond in position to the ten line and private'contacts in each of the levels in the banks above, while the, first is'set slightly ahead of the first of the others, and is engaged by the test wiper 94 when in normal position. The lower semi-circular clamping member 314 is constructed somewhat ditferently from ordinary practice and has a projecting arm 315 atthe left which is bent at right angles and extends vertically along side of the line and private banks. This vertical member 315 carries a strip of ten vertical test contacts which are held in position so that they are engaged by the test wiper 93. lVipe r 93 1s adapted to be moved vertically with the auxiliary shaft 312, but does not rotate with the shaft. 1 The rotary test wiper 94 is mounted on the mainv shaft 300 and although it is loosely mounted upon the said shaft, it is rotated whenever g, the shaft turns by means of-the-pin 317.,

which fits in a slot 318 in the main shaft; lviper 94, however, does notrise vertically, being held in position by the crossbar 316 attached to the lower'ends of the bank rods. The lower hub of the wiper assembly fits in a circular bearin in this member 316 and is held loosely in p ace by means of a lock nut.

Having given a general description Of'thG- while the telephone number at substation A is #XXQS. V

\Vhcn the receiver is removed at the callingstation a circuit is completed for the tens and units relays 17 and 18, and the line relay 1(; over the following path: Ground at G, winding ot units relay 18, resting contact of armature 21 and the said armature, line conductor 12, to and through the telephone at substation A, conductor 11, resting. contact of armature 20 and the said armature, upper winding of relay 16, and the winding of thetens relay 17 'to battery. Upon the closure of the above circuit relays 17 and 18 are energized, while relay 16 is operated sufficiently-to close the make contact at its armature 19. This relay is marginally adjusted and when energized over the line circuit it is operated sufficiently to close the contact named, but does not openthe break contacts at armatures 20 and 21. When the units relay .18 pulls up it removes ground fromv the third testcontact in the rotary test banks of all the finder switches in the group having access to the calling line, and

the tensrelay 17, upon energizing, removes ground from the second test contact in the vertical test banks of these finder switches. At the same'time, relay 17 connects ground to the starting wire 80 which extends to the second finder switch in the group. This second finder switch is the finder switch F, and assuming that the switch is now'in idle condition a circuit will be completed from the grounded starting wire'80 by way of arma-E ture 60 and its resting contacts, and the winding of line relay 43 to battery. Upon energizing, relay 43 completes a circuit at its armature 68, which includes two branches, the first extending from-the said armature 68'to the right by way of the winding of relay 44, armature 79 and its resting contact, and the winding of the vertical magnet 47 to battery, While the second extends to the left by way of the-resting contact of armature 65 and the said armature, winding of relay 45,

resting contact of armature 78 and the said armature", and the winding of the rotary magnet 48 tobattery. At the same time as these'parallel branch circuits are completed, relay 43 connects'the vertical test wiper 93 to the vertical magnet circuit at a point mid- Way betweenthe said magnet and relay 44,

and alsoconnects the rotary test wiper 94 to the rotary magnet circuit at'a point midway betweenthe said rotary magnet and relay 45. The two test wipers are connected up at armature 67 and 66,v respectively.

VVhether or not the switch will operat vertically now depends-upon whether or not the vertical test wiper 93 is in engagement with a grounded test contact. Since the calling line is a line which terminates in the second level of the finder switch, ground has not been removed from the first of the vertical test contacts but from the second, and it follows, therefore, that relay 44 will be short circuited temporarily, while the vertical ieo magnet 47, being supplied with direct ground by way of the vertical test wiper, will be energized. By the operatlon of the vertical magnet the shaft and wipers are raised one step, and the latter are; brought opposite the second level of bank' contacts. In operating, the vertical magnet closesthe circuit for the interrupter relay 49 and-this relay upon energizing breaks the circuit of the vertical magnet. The vertical magnet is accordingly deenergized and breaks the circuit of relay 49, which thereupon falls back and again closes the vertical magnet circuit. If the second test contact in the vertical test bank is also grounded, the vertical magnet will now be operated again and the switch will be raised another step, the operation continuingv in this manner as'long as the test wiper'continues to engage grounded testcontacts. -But in the present case the calling line is terminated in the second level and the second "test contact, therefore, will have no ground potential upon-it. When test wiper 93 arrives at the second test contact, therefore, it will find no ground potential,

the vertical magnet will not again be ener-j gized, and relay 44 being .no longer short circuited, will be energized in series with the Y the shaft. .The test contact normally engaged by thetest wiper 94 is permanently grounded as indicated in the drawing, and when the circuits of the rotary magnet 48 and relay are completed by the line relay 43 as previously described,-relay 45 will be short circuited and the rotary magnet 48 will be operated. By the operation of the rotary magnet the main shaft of the finder switch is rotated and the rotary test wiper 94 is brought into engagement with the first of the regular test contacts. In operating,

the magnet 48 closes the circuit of relay 50 which, upon energizing, breaks the rotary,

' magnet circuit. The rotary magnet now deing line. This being the case, relay 45 will energizes and breaks the circuit of relay .50,

which thereupon falls back and again closes the circuitof the rotary magnet; ,Sin'ce'the. calling line is terminated. in the third con tact set in the second levelv ground has-been removed from the'third testcontact 1b .the'

units relay 18, and the first testconta: will.

still be groundedfassuming' that the first units relay is not energized by another callremain short circuited and the rotary magnet 48' will again be energized, with the -r'esult that the main shaft is rotated another step, andthe' test wiper 94 is brought into engagement with the second test contact.

" For the purpose of this explanation, let it be. assumed now that thesecond linein the sixth level, or line #XX62, is calling, in which case the second units relay will be energized and ground will have been removed from the second test contact. When the test wiper arrives at the second test contact, therefore, it will find no ground potential, the rotation of the switch will cease, and relay 45, being no longer short circuited, will energize in series with rotary magnet 48. Relay 45 is of high resistance like relay 44, and the rotary magnet is not aifected. The vertical; movement of the switch has already ceased, and relay 44 is now in energized position. In addition to the functions already explained relay 4.4 closes a circuit at its armature 73 for the wiper release magnet 52 and this magnet, upon energizing, releases the auxiliary shaft so that the line and private wipers of the finder switch are instantly rotated onto the second contact set in the second level. As soon as the auxiliary. shaft reaches its normalposition with respect to the main shaft, contact springs 54 and 55 are closed. Two circuits may now be tracedwhich have been closed by the joint energization of relays 44 and 45.- The first f tliese extends from ground by way of the winding of slow acting relay 42, sprmgs 55 and 54, armature 72 and its working contact,-- working contact of armature 76 and the said armature, and the winding of the rotary magnet 48 to battery. Upon the closure of this circuit relay 42 is energized. The second circuit referred to is a test circuit and extends from ground byway of the working contact o armature 77 and the said armature, armature 74and its working contact, the upper winding of relay 41, and the normally closed contact springs controlled by armature 58 of relay 40 to the 195 private wiper 91. At this point, however, the circuit is open, for according to the previous assumption the only two calling lines are the line of substation A which is termi- -nated in the third contact set in the second tact set in the second level is not calling, its

line relay will not have been energized and the bank contact now engaged by the private wiper 91 will not have been connected through to the cut-off winding of the asso elated line relay. Thetestrcircuit described,

.-therefore, will. not becompleted, and relay 41 will not be energizeth \Vhen relay 42 attracts its armature 64 itprepares a circuit for its rotary magnet 48, and at its armature 65 breaks the circuit of rela 45.- The lat ter relay, therefore, falls bac closes the rotary magnet circuit at the resting contact of its armature 7 6, and breaks the circuit of relay 42 at the working contact of the same armature. Being slow acting, relay 42 is not deenergized -for an instant, and the rotary 9 magnet 48 is thus operated to rotate the shaft and wipers into engagement'with the third set of contacts in the second level, test wiper 94 being moved at the same time into engagement with the third test contact in the rotary test bank. The circuits are now in the same condition as when the rotary movement of the switch was first initiated, and the rotation of the switch will be continued if necessary until the-test wiper 94 locates another ungrounded test contact.

But in the present case, the calling line is terminated in the third set of contacts in the second level, upon which the switch'wipers'are now resting, and ground has been removed from the test contact now engaged by the test wiper 94. by the operation of the units relay 18; It follows, therefore, that the rotation of the switch will again be stopped and relay 45 will again lie-energized. As before, circuits are now completed simultaneously for relay 42, and for the upper winding of relay 41. This time, since the private wiper 91 is now in engagement with bank contact 31, the latter circuit is complecd by wayof armature 19 and its working contact, and cut-oft winding of relay 16 to battery. Relays 41 and 16 are accordingly energized in series, and the latter relay disconnects line conductors 11 and 12 from the tens and units relays 17 and 18 I at armatiires 20 and 21,- respectively. Relay 41 energizes slightly before relay 42, and at its armature 62 closes a shunt around the break contact at armature of the latter relay, and thus prevents opening of the cir- (hit of relay 45. In addition relay 41 completes a circuit for the switching relay 40 which extends from ground by way of arma-' ture 69 and its working contact, armature 63 and its working contact, lower winding of relay 4t, and the winding of relay 40 to bat tery.'- Upon attracting its armature 58, relay 40 disconnects private wiper 91 fromthe circuit including the upper winding of relay 41, and connects it instead to the circuit-v just established, which includes. the switch ing relay 40, and the lower winding of relay 41.,

It is noted that the release trunk conductor 97 extending to the first selector switch 1), Fig. 2, is connected to this circuit at a point midway between relays 40 and 41.-

In addition to the operations described, switching relay 4'0 disconnects ground from armature 64 of relay 42 by means of its working contacts, trunk conductors 96 and v 98,and armatures 114 and 116 of the switchselector D in the manner above explained,

the line relay 100 is energized over the line circuit, and closes a circuit for the slow acting release relay 101. Upon energizing, the latterrelay prepares a circuit for slow acting relay 102 at armature 108, and at armature 107 connects ground to the release trunk conductor 97, thereby establishing a holding circuit which may betraced by way of the said conductor 97, and through the winding of the switching relay 40 of the finder switch F to battery, and also by way of armature 58 and'its working contact, private wiper 91, bank contact 31, and armature 19 and its working contact, and the cutoil winding of relay 16 to battery. This holding circuit serves to maintain relays 40 and 16 energized throughoutthe duration of the'connection. Ground is also placed upon the private normal conductor 14 which extends to multiply connected test contacts in 'circuit having been broken by the operation of the switching relay 40. Upon deenergizrelay 43 disconnects the test wipers 93'. and 94 and breaks the circuits of relays 44 the banks of the connector switches which have access to the line of substation 1 1,there-,

and 45, and also disconnects ground from the lower winding of relay 41. In addition, at its armature 70, relay 43 extends the start ing wire 80 by Way of starting wire 81 to the'third finder switch of the group. If-

none of the other lines terminating in the second level are calling at this time the tens relay 17 will already have been deenergized and ground will have been removed from the starting wire 80. If, however, some other line in the second level is calling relay 17 will remain held up and the third finder switch will be started and will operate to connect with the calling line in the same way as has just been described in the case of the finder switch F. -v

The foregoing operations by which the line of substation A has been extended through the medium 'of the finder switch F into connection with the first selector D have all occurred automatically responsive to the removal of the receiver from the hook. The calling subscriber may now operate his calling device in accordance with thefirst digit in the desired number, which is the digit 4.

As a result four interruptions are produced in the line circuit and the line relay 100 at the selector D is deenergized momentarily four times. Although its circuit is broken momentarily at each deenergization, theslow acting relay 101 remains inoperated position and a series of four impulses are transswitching relay 105, and the winding of relay 103 to battery. Relay 105is accordingly now in operated position, but since this re lay is of high resistance, relay 103, which is of relatively low resistance and is marginally adjusted, is not operated. Now

' when the slow acting relay 102 energizes responsive to the impulses received from the line relay 100 it connects the grounded release trunk conductor 97 to the junction of relaysv 105 and 103, thereby short circuiting the former relay and closing a direct circuit for the latter relay which thereupon energizes. Upon attracting its armature 111, relay 103 closes a locking circuit for itself by way of the resistance 127, and at armature 112 prepares a circuit for the switching relay 104, and at its armature 113 prepares the usual testing circuit. Relay 105 is short circuited when relay 102 is firsLenergized, and since the latter'relay remains in operated position while four impulses are being transmitted to it the short circuit .is maintained long enough to cause relay 105 to fall back. In doing so it breaks the connection to the release trunk at armature 118 and since its initial energizing circuit has already been opened at armature 111 of relay 103, relay 105 cannot again .be operated.

Thus it will be seen that the wiper set comprising wipers 121, 122, and 123 are connected for use. At the end of the series'of impulses, relay 102 falls back and at its tact, working contact of armature 112 and armature 109 completes a circuit extending through the switching relay 104, and the steppingv magnet 128, in "series to battery. At the same time, at its armature 110 relay 102 connects the test wiper 122 to the above circuit at. a point midway between the said relay and magnet. The operation now depends upon whether the test wiper 122 is in engagement with a grounded test contact, or not. If the trunk line terminating in the bank contacts uponlwhich the wiper set in use is standing is busy, the test contact engaged by the test wiper 122 will be grounded, the switching relay 104 will be short circuited, and the stepping magnet 128 being supplied with direct ground by way of the test wiper will operate'as a buzzer to advance the switch wipers step by step in searchof an idle trunk line. This move ment will continue aslong as the test wiper 122 engages grounded test contacts, but in the present case we may assume that when the selector D is taken for use wipers 121, '122, and 123 are standing upon the contact set in which is terminated the trunk line extending to the second selector E, and it may.

be assumed furthermore that this trunk line is idle. Under these circumstances when the slow acting relay 102 falls back and closes the circuit of the switching relay 104, said relay will not be short circuited and no rotary movement of the switch will take place, but the said relay 104 will pull up at armatures named, armatures 117 and 120 and their resting contacts, wipers 121 and 123, bank contacts 130 and 132, and armatures 160 and 163 and their resting contacts to line relay 151 of the second selector E .and to ground, respectively.

When the calling line is extended to the" second selector E in this manner, line relay.

151 is .energizedfover the line circuit and closes a c1rcu1t for theslow actingrelease relay 152. Upon energizing, the latter relay.

prepares a circuit for the vertical magnet 155 atits armature 1 65, and at its armature 164 closes a holding circuit which extends from ground by way-of the working contact of armature 164 and said armature, release trunk conductor 134, test contact 131, test wiper 122, resting contact of armature 119 and the said armature, working contact.

of armature 113 and the said armature, rest ing contact of armature and the said armature, armature and its working coning circuit is established before the slow acting release relay 101 of the selector D has had time to deenergize,-and serves to -maid.

tain relays 103 and 104 energized during.

the Qonnection.

It may be well to pause a .1n 01 nent at this point and consider the operation of the selector D a little more fully. The system herein contemplated has a capacity of 2,000 lines, comprising two groups, which may-be termed the 1,000 grou and the 4,000 group.

In other words, the rst-digit in the telephone numbers assigned to one of the groups of lines is always the digit 1, while the first digit in the telephone numbers assigned to the other group of lines is the digit 4. lVhen I 105 will be short circuitedlong enough during the transmission of a series of impulses correspondingto said digit to cause it to fall back, break its locking circuit, and connect up the normally connected set of wipers,

all as described in detail in the foregoing paragraphs. However, if the first digit in the desired number is the digit 1 relay 105 will be short circuited only momentarily, and since this relay is slow acting it will not fall back but will remain locked up by way of its armature 118, notwithstanding the fact that its initial energizing circuit ,is broken at armature 111 of relay 103, and the wiper set comprising wipers 124, 125, and 126 will remain connected for use. The subsequent operation-of selecting an idle trunk will take place the same as in theother case, except that since the a ternative wiper set is being used a trunk line will be used which extends to a second selector in a different group. It will be seen then that the selector D may have access to two different groups of second selectors corresponding to the two different thousands, and although this is a small number as compared to the usual ten groups which are accessible to the ordinary standard type of first selector, yet under certain circumstances two thousand groups are all that is required, and in such a case a switch of this type is very desirable. The selector D has no complicated stepping mechanism such as is used in the ordinary selector switch and is, therefore, much cheaper to construct. decided advantage in that its wipers are normally in engagement with a set of bank contacts, and in the majority of cases no rotary movement of the switch isfrequired.

Proceeding now with the explanation, the connection hasbeen extended as far as the second selector E. l-Vhen the calling subscriber operates his calling device in accordance with the next digit in-the number, which is the digit 5. a series of five interruptions is produced in the circuit of the line relay 151 and said relay is accordingly deenergized momentarily five times. At each deenergization of the line relay an impulse of current is transmitted through the slow acting series relay 153 and the vertical magnet 155, and the latter is operated in the usual manner to raise the switch shaft step by step until the wipers 180, 181, and 182 .stand opposite the fifth levelof bank contacts. Relay 153 is energized in series with the vertical magnet and since it is slow act- It also .has a ing it retains its armature attracted until the impulses cease. At the end of the vertical movement" of the switch, relay 153 .is

deenergized and since the off normal springs 158 have been closed (these springs are closed at the first upward movement of the shaft) a circuit is completed for th'erotary magnet 156 as follows: vFrom the grounded armature 162 by way of the said armature and its rest-ing contact, armature 168 and.

its working contact, off normal springs 158, armature 166 and its resting contact, armature 167 and its resting contact, and the winding of the rotary magnet 156 to battery. 'Therotary magnet is accordingly operated and advances the switch wipers into engagement with the first set of contacts in the level opposite which they have been raised. In operating, the rotary magnet closes a circuit for the interrupter relay 154;. Upon energizing, relay 154 connects the test wiper 181 with the lower winding of the switching-relay 150 at armature 168, and'at the same time, or a little later, preferably, breaks the circuit of the rotary magnet at armature 167. The operation now depends upon whether the first trunk line in the selected level is busy or-idle. If this trunk line is busy, the test contact engaged by the test wiper 181 will have aground potential upon it, and since the lower-winding of relay 150 is connected to ground the said relay 150 will not be operated. The rotary magnet deencrgizes when its circuit isbroken at armature 167 and breaks the circuit of the interrupter relay 154 which accordingly falls'back and again completes the rotary magnet circuit, the rotary. magnet being again operated to advance the. switch wipers into engagement with the next set of bank contacts. This operation will continue .until the test wiper 181 arrives at a test contact having a battery potential upon it,

the rotary magnet, a circuit will be completed' for the switching relay 150 which extends from ground by way of-the lower winding of relay 150, armature 168 and its working contact, test wiper 181, test contact 184, release trunk conductor v187, armature 216 and its resting contact. armature 227 and its resting contact and the upper winding of the line relay 201 of the connector H to battery. Upon the closure of the above circuit, relays 201 and 150 are energized in series and the latter relay closes a locking circuit for itself at its armature 161, at the sam'e time connecting the grounded release. trunk conductor 134 to the test wiper 181 in order to make the selected trunk line busy.

Belay 150 also breaks the rotary magnet circult at its armature 162, and at its armatures 160 and 163 extends the incoming trunk conductors, by way'of wipers, 180 and 182,

bank contacts 183 and 185, trunk conductors 186 and 188, and the normally closed contacts at the reversing relay 200 to; the upper armature 215, and. at its armature 216 connects lground to the release trunk conductor 187, t ereby establishing. a holding circuit whlch may be traced by way of the said conductor 187, test contact 184, test wiper 181, and the make contacts at armature 161 Y to the release trunk conductor 134, where it. reviously described holding cirjoins the cuit exten ing back through the selector D and the finder switch F. The upper wind ing of the switching relay 150 is connected to the holding circuit at armature 161, and this relay is, therefore, held up throughout the duration of the connection.

The calling subscriber ma now 'operate his calling device in accor ance'jwith the next digit in thedesired .number f-As aresult six interruptions are produced in the line circuit in the usual manner and the line relay 201 is deenergized momentarily six times, ateach deenerg'ization sending an im pulse of current through the slow acting relay 203 and the vertical magnet 208 in se-.

ries. By the-operation of the vertical mag- 4 net,.the connector shaft is raised step by step until the wipers are raised opposite the sixth levelof bank contacts. The slow acting relay 203 is energized in series with the vertical magnet and retains its armature 21 7 attracted during the series of impulses,

thereby preventing the-vertical magnet circuit from being opened by the shifting of the. of? normal springs 211, 212 and 213, Y which takes place, at the first upward movementof the switch shaft. At the end of the vertical movement of the switch, the slow acting relay 203 falls back and transfers the operating circuit to the' rotary Imagnet 209. .1" H Y The calling subscriber may now operate his callingdevice for the next and final digit in the number, this being the digit 7. In response to the interruptions thus produced in the line circuit the line relay 201 is deen ergized momentarily seven times, and at each deenergization transmits an impulse of current through the rotary magnet 209. By the operation of the rotary magnet the switch wipers 250,251, and 252 are rotated step by step and are finally brought to rest in engagement with the particular set of uopeqsqus ;0 can eq; qorqm ur sqomuoo qnuq 'A'is termlnated, these contacts being indicated by the reference characters 253, 254,

and 255. Theslow actingrelay 206 is connected. to the operating circuit and is energized in parallel with the rotary magnet 209, its armatures being held up continuously throughout the rotary movement of the switch. At armature 225, relay; 206 connects the test wiper 251 to the winding of the test relay 205, and at its armature 224 relay 206 closes a shunt around the break contact at armature 222 of the test relay, the latter operation being a precautionary measure which prevents the rotary magnet circuit from beingopened in case the test wiper should engage a grounded contact while the switch is rotating. v

It may be assumed first that the called line is busy when connected with, as explained above. Under these circumstances, when the test wiper 251 comes to rest in engagement with test contact 254 it will find a ground potential. thereon and the test relay 205 will be. energized. -An instant later, when the slow acting relay 206 falls back at the end of the rotary movement of the switch, the test relay establishes a locking circuit for itself at its armature 221; The test relay also breaks the rotary magnet circuit at its armature 222, and at its armature 223 connects a lead from the busy signalling machine to the lower side of the calling line. By this operation an audible busy signal is transmitted to the calling 1254 it will find no ground potential and the test relay 205 will not be energized. Then,

wvhen the slow acting relay 206 falls back an instant later, a circuit is completed for the switching relay 207 over the following path: From the grounded release trunk conductor 187 by way of armature 221 and its resting Contact, upper winding of relay 207, resting contact of armature225 and the said armature," test wiper 251, testcontact 254,

private normal conductor 264, and the cutoff winding of the combination line and cut-' off relay 270 to batte'ry. Relays 207 and pletion of the above circuit, and the latter relay operates todisconnect the conductors 260 and 261 ofthe called line from their the exchange.

270 are energized in series upon the comnormal battery, and ground connections at In the connector, when the switching relay 207 is energized it establishes a locking circuit for itself at its armature 229, grounds the test wiper 251 at armature 228, breaks the connection at its armature 227 which extends from the upper winding of the line relay 201 to the resting contact of armature 216, opens the rotary magnet at armature 230, and at armatures 226 and 231 connects up the upper and lower line wipers 250 and 252. Ringing current from the generator GEN is now projected 'intermittently out over the called line in scribers may converse as desired. The

transmitter at the calling station A is supplied with talking current through thewindings of the double wound line relay 201 of the connector H, while the transmitter at the called station A is supplied with talking current through the windings of the double wound back bridge relay 200. The latter relay is energized immediately following the energization of the rihg cut-off relay 204 and reverses. the direction of current flow in the calling line. This operationis of no particular utility in connection with the apparatus shown herein, but is a standard operation provided for in order to control measured service equipment where such equipment is furnished.

At the end of the conversation, both subscribers will hang up their receivers The" release of the connection is controlled by the replacement of the receiver at the calling substation A in the following manner:

When the receiver is hung up, the line and release relays 201 and 202 of the connector H are deenergized and jointly close a circuit for the release magnet 210, which.op--

crates to restore the connector to position in the usual manner. the holding circuit extendin selectors E and D, finder switch F, and the cut-off winding of the combination line and cut-off relay 16, and all relays in the switches named which have been held up over the grounded holding circuit are permitted to deenergize. At the selector E, when the switching relay 150 falls back a circuit is completed for the release magnet 157, which operates to restore the selector switch to normal position. In the selector- D the wipers are not restored; relays 103 and 104 simply fall back, and the latter re- Relay 202 also breaks back to the lay disconnects the wipers. In the finder switch F, when the switching relay 40 is deenergized it closes a circuit'i'or the .release magnet 51, which extends by way of the grounded armature 69 and its resting contact, resting contact of armature 59 andv the said armature, rotary off normal spring 53 and its working contact, and the winding of the release magnet 51 to battery. By the operation of the release magnet 51 the switch shaft is restored to its normal position, and roller 321 which is carried-by the member 310 on the auxiliary shaft 312 is again locked at the latch of armature 322. It is noted that the off normal spring 53, whose function it'is to breakthe release magnet circuitafterthe switch has been fully restored, is operated on the first rotary movement of the main shaft, rather than on the first vertical movement as is the usual case and this is necessary on account of the fact that the line and private wipers of the finder switch normally stand opposite the first level of bankcontacts, from which it will be seen if the calling line is a line terminating in the first level no vertical movement of the switch will take place. Therefore, the off normal s ring 53 is arranged to be operated on the rst rotary movement, as stated, in order toinsure that it will b actuated in all cases.

Having described my invention, what I consider to be new and. desire to have protected by Letters Patent will be pointed out in the ap ended claims.

What claim as my invention is:

1. In a switching device for automatic telephone systems, the combination with a contact member adjustable and movable in 'o'nlytwo directions, of two devices for controlling the'adjustment of said member in said two directions, respectively, and means -for operating said devices simultaneously.

2. In a. switching device for automatic telephone systems, the combinatlon, with a traveling contact member movable in two directions, of 'mechanism for moving said member in one direction, another mechanism operable simultaneously with said first mechanism for determining the extent of movement in the other direction, and means for delaying the movement of said contact member in the other direction until after the movement in the first direction is completed.

3. In' a switching device for automatic telephone systems, apair of wipers movable simultaneously in difierent directions, and a third wiper movable simultaneously with one of said first wipers and in the same direction, and movable subsequently in the same. direction as the other of said first wipers. I V

4. In a switching device for automatic telephone systems, a shaft movable vertically and rotarily, stepping magnets for moving said shaft longitudinally, and means raising and rotating said shaft, a vertical ratchet rotatable on said shaft, and a rotary ratchet slidable on said shaft vertically.

5. In a switching device for automatic telephone systems, a'shaft movable vertically and rotarily, a vertical ratchet rotatable on said shaft, a rotary ratchet slidable on said shaft, and stepping magnets and armafor rotating it, an auxiliary shaft, means for causing said auxiliary shaft to move longitudinallywith said main shaft, and means for rotating said auxiliary shaft after the rotation of the main shaft has ceased.

8. In a switching device for automatic telephone systems, a main shaft and an auxiliary shaft, means for moving both shafts longitudinally, means for rotating the main shaft, means for locking the auxiliary shaft agalnst rotation, and means for releasing the auxiliary shaft after the rotation of the main shaft is Completed.

9. In a switchingdevice for automatic I telephone systems, a main shaft, an auxiliary shaft rotatable on said main shaft, means causing sald auxiliary shaft, when unrestrained, to assume a normal position relative to said main shaft, means for moving both shafts longitudinally, means for rotating the main shaft, means for locking the auxiliary shaft against rotation, and

.means for releasing the auxiliary shaft'to.

. permityit to assume itsnormal position; I

10.. In a telephone system, an automatic switch having primary and secondary group and'lin'e selecting movements, means whereby said switch is caused to perform lines, a finder switch for extending calling both movements simultaneously, and means for operating said switch in atertiary mover ment to an extent determined by the secondary movement to. connect'with the selected line. v V

. 11. In a telephone system. a plurality of groups of lines,--a switch having vertical movement to select a group and rotary movement toi select a line in the selected group, and means for causing said switch to 'perform both movements simultaneously.

12. In a telephone system, a plurality of groups of lines, an automatic switch having group and line selecting movements whereby any line in said groups. may beselected,

means for causing said switch to perform both of said movementssimultaneously, and means for rendering the line selecting movement inefiective until after the group selecting movement is completed.

13. In a telephone system, an automatic switch for use in connecting .calling and called lines, primarymid secondary operating magnets in said switch for operating the same to establish aconnection, means for operating said magnets simultaneously,

a connecting wiper in said switch directly responsive to said primary magnet, and a trip magnet for causing said wiper to respond to said secondary magnet.

14. In a telephone system,'an automatic switch for use 1n connecting a callingand called line, a movable contact member in said switch adjustable only in two directions at right angles to each other to close a contact in the talking circuit, primary and secondary operatingmagnets governing the adjustment of said member in said two directions, respectively, and means for simultaneously actuating said magnets to perform their respective functions as set forth. V

15. In a telephone system, an automatic switch for connecting lines, and a wiper in said switch having step by step primary selecting movement and continuous secondary selecting movement.-

16. In a telephone-system, an automatic and line selecting operations for'connecting lines, a wiper in said switch, means for giving said wiper a step by step movement during a group selecting'operation, means for preventing movement of said wiper during a line selectin operation, and means for giving said wiper a continuous movement after the line'selecting operation is'completed.

" 17. In a telephone system, an automatic .switch for use in connecting lines, a line wiper in said switch having successive primary and secondary movements, and mary and secondary test wipers movable simultaneously to determine the movement of said line wiper. i

18. In a telephone system, a group of switch adapted to perform successive group' pri- - operating said magnets simultaneously re calling,

1 lines, a finder switch for extending said lines when calling, primary and secondary operating magnets in said switch, means for sponsive to a call to cause said finder to locate the calling line, and means including a two motion wiper shaft controlled by said magnets for connecting with a calling line when the same is located.

21. In a telephone system, subscribers lines, a finder-switch for extending said lines when calling,- primary and secondary test wipers movable simultaneously to locate a calling line, and line wipers movable first primarily and thensecondarily to complete the connection. v

22. In a telephone system, groups of lines, a finder switch for extending said-lines when calling, means for starting said switch responsive to a call, ,common group and unit test contacts in said switch, group'and unit test wipers in said switch cooperating with said contacts to stop said'switch on the calling line or on another line having a lowerunits designation, and means for automatically restartingsaid switch in case the line on which the switch is stopped is ,not calling.

23. Ina telephone system, grou s of lines, a finder switch for extending said lineswhen means for starting said switch responsive to a call, common group and unit test contacts in said switch, group and unit test wipers in said switch cooperating'with said contacts to stop said'switch on the calling line, and means for automatically restarting said switchin case it is stopped on the wrong line by-a second calling km in a different group, I

24. In a switching device for automatic telephone systems, a contact member, suportin means forv said member. restrictin b b it to movement in two perpendicular planes,

' and simultaneously operable means for controlling the extent of said movements.

25. In a switching device for automatic telephone systems, a wiper having movement in only one direction, a second wiper having movementfin only one direction, ut in a different'direction from thedirection of movement of said first wiper, electromagnetic mechanism for moving said wipers s1- .anultaneously, and athird wiper movable under controlofboth said firstand second wipers 26. Ina finder switch, a line wiper, primary and secondary test wipers. and means for progressively advancing said test wipers simultaneously to cause theswitch to locate a calling line and engage the same with said line wiper.

27.. In a switching device for automatic telephone systems, vertical and rotary oper ating' magnets, and a shaft arranged for simultaneous vertical and rotary movements under control of said magnets.

switch co-operating with said test contacts.

28. In a switching device for'jautomatic telephone systems, vertical and rotary oper-' ating magnets, armatures and pawls for said magnets, a rack engaged by the vertical pawl, a ratchet wheel engaged by the rotary pawl, and a shaft which is lifted androtated simultaneously by said rack and ratchet, respectively.

29. In a telephone system, a plurality of lines, a finder switch, means for startingand stopping said finder, a restarting circuit closed automatically wheneverthe switch is stopped, a test' circuit closed at the same time as said restarting circuit, and means controlled over said test circuit for rendering the restarting circuit ineffective in case g the line upon which the finder is stopped is a calling linep .30. In a telephone system, aplurality of lines, a finder having primary and secondary;

movement, means common to. said lines for causing the advance of said finder in twoseparate movements to a line designated by said common means, separate means in said finder for testing the line so located to asto cause the finder to connect with the line upon whichit has stopped provided such line is actually calling.

32. In a telephone system, groups of lines, a finder switch, common group and unit test contacts in said switch, '1') i an individual test contact in said switch a; plurality of finder controlled by said individual means for eachline, group andunit test wipers in said switch co-operating with said common test contacts, and another test wiper in said individual 33. In a telephone'system, a plurality of groups of lines, afinder switch. common group and unit test contactsv in said'switch, an individual test contact in said switch for'each line, group-and rmit test wipers in said switch co-operating with saidcommon testcontacts, another test wiper in said switch co-operating with said individual test 7 contacts, and circuit arrangements such that all-three test wipers'are used to definitely stop saidfinder on a calling line. i

34. In a telephones'ystem, a plurality of groups'of lines, a finder switch, common group and unittest contacts in said switch,

an individual test contact in said switch for;

each line, groupand unit test wipers in' said switch co-operating with said common test contacts, another test wiper in said switch co-operating with said individual test contacts, means in said finder controlled over said group and unit test wipers for tentatively stopping the finder on a supposed calling line, and means in said finderfor making the stop a definite one in case the line is actually calling.

In a telephone system, a pluralityof lines, a finder switch, common tens and units.

relays for indicating calling lines tosaid finder, and means for causing said finder to passby anon-calling linev having the same tens designation as a calling line for which the finder is hunting and the same units designation as .a' second calling line.

36. In-a telephone system, a plurality'of lines, a finder switch operating according to the rectangular coordinate system, a device common to each gronpof lines of which the ordinates are thesame, a device common to each group of lines of which the abscissas are the same, means whereby any line when calling causes the operation of the devices assigned to the'respective groups to which such calling line belongs, the two operated devicesbeing effective to designate the calling line-to. said finder, means whereby another calling line causesthe operation of two more of said devices, and means for causing-said finder to pass by a non-calling line which is' falsely indicated as calling by one of the devices operated by the first calling line in conjunction with one of the devices operated by the secondealling line.

37. In a telephone system, a plurality of lines, tens relays, each common to a group of said lines havingthe same tens designations, units relays each common to a group of said lines having the same units designa:

- spring.

tions, a line relay individual to a line and connectedin series with the units and tens relays which correspond to the groups to which such line belongs, and a similarly connected line relay for each of the remaining lines. a

38. In an automatic switch, two shafts, a spring connectin said shafts, electro-magnetic means for riving one shaft to a definite point while the second shaft is held against movement, and means for releasing the second shaft to permit the same tofollow said first shaft under tension of said .39. In an automatic switch, two shafts, a

spring connecting said shafts, electro-mag-' netic means for driving one shaft, means for holding the second shaft, and means for releasing saidsecond'shaft during the move mentof said first shaft,whereupon the said second shaft is impelled by said spring to overtake-said first shaft and thereafter partrical condition has been altered, and means for automatically restarting sald finder in case the same is stopped with its test wiper in engagement with a test contact whose electrical condition has been altered due to some cause other than that the-associated line is calling.

" Signed by me at Chicago, Cook County,

' Illinois, this 15th day of Nov. 1920.

RODNEY G. RICHARDSON. 

